TW201838503A - Tape substrate for conveyance in plating process and tape for conveyance in plating process - Google Patents

Abstract

The present invention provides a substrate suitable for forming a tape for conveyance in plating process, the tape for conveyance in plating process is used in a process of sticking a flexible printed wiring board, conveying it to a plating bath and plating the wiring board wherein shrinkage due to heating during plating is suppressed, and transfer of an adhesive contained in an adhesive layer to the flexible printed wiring board side is suppressed too. Specifically, the present invention provides a tape substrate for conveyance in plating process which is a substrate used for forming a tape for conveyance in plating process used in a process of sticking a flexible printed wiring board, conveying it to a plating bath and plating the wiring board; wherein, (1) the substrate becomes the tape for conveyance in plating process due to application of an adhesive layer, (2) the substrate is an unstretched film composed of a single layer or multiple layers, and at least one layer contains polybutylene terephthalate and an inorganic filler.

Description

   Base material for plating step conveyance and tape for plating step conveyance   

The present invention relates to a substrate for a belt for transport in a plating step and a belt for transport in a plating step.

When manufacturing a flexible printed wiring board, there are many steps such as alkali development, etching, peeling resist, plating, and mounting of electronic components. In order to transport the substrate in the manufacturing process to each step, it is generally A substrate transfer carrier is used. In recent years, in order to cope with the flexibility of a substrate using a flexible material and the efficiency of manufacturing steps, a resin substrate having flexibility and an adhesive layer are used in combination as a carrier for substrate transportation.

For example, Patent Document 1 discloses a substrate transfer carrier, which is used for transferring a transported object such as a printed wiring board. The carrier includes a flexible support, which is flexible and bendable, and an adhesive layer, which is fixed to the foregoing. The flexible support can track the deformation when the flexible support is deformed, and is in a peelable manner with the lower surface of the substrate; and a specific positioning mask is attached to the aforementioned adhesive layer so that The method of peeling is close, and it has a positioning penetration part (request item 1 etc.). Then, Patent Document 1 discloses that, for example, polyimide (PI), polymethyl methacrylate (PMMA), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), As a flexible support (such as paragraph [0015]), a resin film such as polypropylene (PP) can be used as an adhesive layer (for example, urethane resin, polyvinyl alcohol resin, silicone resin, etc.) [Paragraph [0018]), using the substrate transfer carrier to sequentially transfer substrates to steps such as a solder paste printing step, an electronic component mounting step (paragraph [0045]).

    [Prior technical literature]         [Patent Literature]    

[Patent Document 1] Japanese Patent Laid-Open No. 2014-72390

However, in the steps of transferring a flexible printed wiring board to a plating tank using a conventional substrate transfer carrier as disclosed in Patent Document 1, and performing plating on the terminal portion (electrode portion) on the substrate, Several questions. For example, when a biaxially stretched PET film, a biaxially stretched PEN film, or the like is used as a support for a substrate transfer carrier, the heating during the plating step (including heating before and after the plating process) is about 150 to 200. ℃) caused shrinkage of these films, and caused curling problems due to the shrinkage difference from the PI film used for flexible printed wiring boards. In addition, when a biaxially-stretched PEN film is used, there are problems that the film is expensive and difficult to use. Furthermore, when a PI film is used as a support for a substrate transfer carrier in order to reduce the shrinkage difference, there is a problem that the adhesive contained in the adhesive layer is transferred (adhesively transferred) to the flexible wiring substrate side.

Accordingly, the main object of the present invention is to provide a base material suitable for forming a transfer belt for a plating step, wherein the transfer belt for the plating step is "attached to a flexible printed wiring board and transferred to the plating The user who covered the grooves and applied the plating step to the wiring board ", and the shrinkage caused by the heating in the plating step was suppressed, and the adhesive contained in the adhesive layer was used for flexible printed wiring. The transfer on the substrate side is also suppressed. Another object of the present invention is to provide a transfer belt for a plating step in which an adhesive layer is provided to the substrate.

As a result of earnest and repeated research in order to achieve the above-mentioned object, the present inventors have found that the above-mentioned object can be achieved by a resin laminated body having a specific layer structure, thereby completing the present invention.

That is, the present invention relates to a substrate for a belt for transporting a plating step and a belt for transporting a plating step described below.

1. A tape substrate for conveyance of a plating step, which is a substrate for forming a tape for conveyance of a plating step, wherein the tape for conveyance of the plating step is "attached to a flexible printed wiring board and conveyed to it" The users in "plating tanks and applying plating to this wiring board"; (1) the aforementioned substrate is a belt for transporting the aforementioned plating step by providing an adhesive layer; (2) the aforementioned substrate is a single substrate An unstretched film composed of multiple layers or layers, and at least one layer contains polybutylene terephthalate and an inorganic filler.

2. The belt substrate for transport in the plating step according to the above item 1, wherein the layer containing the aforementioned polybutylene terephthalate further contains a material selected from the group consisting of polyethylene terephthalate and polyethylene naphthalate. At least one of the group consisting of ethylene glycol, polycarbonate and polybutylene naphthalate.

3. The belt substrate for transfer in the plating step according to the above item 1 or 2, wherein the inorganic filler contains fibrous potassium titanate.

4. The belt substrate for transport in the plating step according to item 3 above, wherein the average thickness of the fibrous potassium titanate is 0.1 to 0.8 μm, the average length is 5 to 30 μm, and the average aspect ratio is 10 to 100.

5. The belt substrate for transfer in the plating step according to any one of the above items 1 to 4, wherein the inorganic filler contains zinc oxide in a tetrapod shape (also referred to as a wave block shape).

6. The belt base material for transport in the plating step according to any one of the above items 1 to 5, wherein the inorganic filler contains glass fibers.

7. The belt substrate for conveyance in the plating step according to any one of the above items 1 to 6, is composed of a layer having an outer layer A, an intermediate layer B, and an outer layer C in order; (1) the foregoing The intermediate layer B contains the polybutylene terephthalate and the inorganic filler; (2) The outer layer A and the outer layer C do not contain an inorganic filler.

8. The belt base material for transport in the plating step according to item 7, wherein the outer layer A and the outer layer C contain the polybutylene terephthalate.

9. The belt substrate for transport in the plating step according to the item 8, wherein the outer layer A, the intermediate layer B, and the outer layer C all further comprise a material selected from the group consisting of polyethylene terephthalate and polynaphthalene. At least one of the group consisting of ethylene formate, polycarbonate and polybutylene naphthalate.

10. The belt base material for transfer in the plating step according to any one of items 1 to 9 above, whose tensile elastic modulus is more than 1500 MPa and not more than 2000 MPa.

11. A transfer belt for a plating step, which has an adhesive layer on a surface of a base material for a transfer belt for a plating step according to any one of items 1 to 10 above.

In the present invention, the substrate for conveyance with a plating step is an unstretched film composed of a single layer or a plurality of layers, and at least one layer contains polybutylene terephthalate and an inorganic filler. In order to produce a plating step transfer tape and use it in "the step of attaching a flexible printed wiring board and transporting it to a plating tank and plating the wiring board", the Shrinkage caused by heating (about 150 to 200 ° C) is suppressed, and transfer of the adhesive contained in the adhesive layer to the flexible printed wiring board side is also suppressed.

1‧‧‧ middle layer B

2‧‧‧ Outer layer A

3‧‧‧ Outer C

4‧‧‧ Adhesive layer

5‧‧‧ transport roller

6‧‧‧ Flexible printed wiring board

a‧‧‧Plating substrate for transportation

b‧‧‧ Belt for transporting plating steps

FIG. 1 is a schematic cross-sectional view showing an example of a tape substrate (a) for transporting a plating step according to the present invention. In the first figure, 1 is an intermediate layer B, 2 is an outer layer A, and 3 is an outer layer C.

FIG. 2 is a diagram showing a step of forming a tape for a plating step transport by providing an adhesive layer to the tape substrate for a plating step transport of the present invention. 4 indicates an adhesive layer.

FIG. 3 is a schematic cross-sectional view showing an example of the layer configuration of the belt (b) for transport in the plating step of the present invention.

FIG. 4 is a schematic view showing a state in which a flexible printed wiring board is attached to the tape for the transportation in the plating step of the present invention, and the transportation roller is rotated and transported.

    1. Base material for transport in the plating step    

The tape substrate for the transport of the plating step of the present invention is a substrate for forming the tape for the transport of the plating step, wherein the tape for the transport of the plating step is attached to a "flexible printed wiring board and attached to it" The users in "plating tanks and applying plating to this wiring board"; (1) the aforementioned substrate is a belt for transporting the aforementioned plating step by providing an adhesive layer; (2) the aforementioned substrate is a single substrate An unstretched film composed of one or more layers, and at least one layer contains polybutylene terephthalate (PBT) and an inorganic filler.

The substrate for transporting the plating step of the present invention having the above characteristics is an unstretched film composed of a single layer or a plurality of layers, and at least one layer contains PBT and an inorganic filler. Therefore, the substrate is prepared by providing an adhesive layer to the substrate. When the tape for transporting the plating step is used in "the step of attaching a flexible printed wiring board and transporting it to a plating tank to perform plating on the wiring board", the heating of the plating step (reach 150 to 200 ° C) is suppressed, and the transfer of the adhesive contained in the adhesive layer to the flexible printed wiring board side is also suppressed.

The tape substrate for transfer in the plating step of the present invention may consist of only a layer containing PBT and an inorganic filler (hereinafter, this layer is also referred to as a "main layer"), or may include a plurality of layers including a main layer and other layers. Made up. In addition, whether it is a single layer or a plurality of layers, the whole must be an unstretched film. In the following, the description is divided into "a form consisting of the main layer only" and "a form consisting of a plurality of layers including the main layer".

    (Consisting of the main floor only)    

The main layer system contains PBT and an inorganic filler. PBT is not particularly limited, and commercially available products can be widely used. From the viewpoint of obtaining good fluidity during film formation, the intrinsic viscosity (IV: Intrinsic Viscosity) of PBT is preferably 1 to 1.6, and more preferably 1.1 to 1.3.

When the intrinsic viscosity is within these ranges, a moderate fluidity can be imparted to PBT, so that it is easy to form an unstretched film containing PBT. In addition, it is difficult to generate a fish eye in the formed PBT-containing unstretched film. The intrinsic viscosity (IV) of PBT in this specification is a value measured according to JIS K7390: 2003.

As for the resin component of the main layer, although it can be composed entirely of PBT, when other resin components (sub-components) are used in combination, the content of PBT is the main component (100% by mass of the resin component of the main layer (50 (Mass% or more) is preferred, 70 mass% or more is particularly preferred, and 85 mass% or more is more preferred.

As the secondary component, at least one of PET, PEN, PC (polycarbonate), and PBN (polybutylene naphthalate) can be used. By using these auxiliary components in combination, the rigidity of the base material for the transport of the plating step can be improved, and the deflection of the transport belt for the plating step during transportation can be suppressed. In this regard, it is desirable that the rigidity of the base material is the same as that of the "PI film used for the base material of flexible printed wiring boards." The tensile elastic modulus is in the range of more than 1500 MPa and less than 2000 MPa. It is preferably within the range of 1700 to 2000 MPa, and more preferably within the range of 1850 to 1950 MPa. In this specification, the tensile elastic modulus is a value measured according to a method based on JIS K 7161: 2014. In addition, by using the above-mentioned subcomponents in combination, it is possible to suppress the occurrence of ripples and deformation on the surface of the substrate when the tape substrate for transporting the transfer step is heated by a heat treatment (for example, about 200 ° C.).

Compared with biaxially stretched PET and biaxially stretched PEN, the shrinkage caused by heating of the unstretched PBT film is suppressed to be low, so its shrinkage caused by heating at about 180 ° C is about 0.5%. In addition, the shrinkage of PET film under the same conditions is about 1.2%, and the shrinkage of PEN film is about 0.6%. In the present invention, since the main layer contains not only PBT but also an inorganic filler which will be described later, the shrinkage due to heating can be further suppressed to be lower than the case where the inorganic filler is not contained. The shrinkage caused by heating at about ℃ can be suppressed to a ppm level (substantially 0%). Therefore, since the shrinkage ratio [ppm level (substantially 0%)] of the PI film used for the flexible printed wiring board is about the same, curling can be suppressed during the plating step.

The inorganic filler is not particularly limited, and commercially available products can be widely used. In addition, since the inorganic filler used in the present invention is used for "transportation of processing steps such as flexible printed wiring boards", the inorganic filler is preferably made of a material that does not cause contamination during heat treatment, and it is A processor (no processor) is preferred. On the other hand, when using a surface-treated product, the surface-treated person of an organic silane, such as a silane-based coupling agent, may be contaminated by the vaporized silicon during heat treatment, so avoid using an organic silane coupling agent. It is preferable to use a surface treated with an inorganic coupling agent such as a titanium coupling agent.

Compared with the resin component, the thermal shrinkage of the inorganic filler is more than one digit smaller. The adhesion between the resin component and the inorganic filler caused by kneading into the resin component can reduce the shrinkage of the resin component (Composite effect). From the viewpoint of further improving the suppression of "shrinkage due to heating" by including it in the main layer, if the effect of the composite material is to be further exerted, a fibrous inorganic filler having a large aspect ratio is used. Better.

The fibrous inorganic filler is not particularly limited, but a fibrous inorganic filler having a smaller fiber diameter is preferred from the viewpoint of further improving the suppression of "shrinkage due to heating". Specifically, fibrous potassium titanate can be mentioned as a preferable example.

As for the fibrous potassium titanate, an average thickness of 0.1 to 0.8 μm, an average length of 5 to 30 μm, and an average aspect ratio of 10 to 100 are preferred, and an average thickness of 0.3 to 0.6 μm, average The length is preferably 10 to 20 μm, and the average aspect ratio is 10 to 70.

By containing fibrous potassium titanate in these forms, the main layer can be kept soft and prevented from becoming hard and brittle, and at the same time, the shrinkage caused by heating of the main layer (especially the shrinkage in the direction of fiber orientation) can be suppressed. To lower. Examples of such commercially available fibrous potassium titanate include potassium titanate fiber (trade name: "Tismo" series) manufactured by Otsuka Chemical Co., Ltd. as a preferable example.

In addition, in general, when a fibrous inorganic filler is mixed into a resin, the fibers are aligned in the MD direction (flow direction of the resin), so the effect of suppressing the shrinkage in the MD direction becomes very large. Although the direction of the resin flow in the mold may be partially aligned in the TD direction (width direction), the shrinkage suppression effect in the TD direction and the thickness direction is smaller than that in the MD direction. From this point of view, from the viewpoint of further improving the suppression of "shrinkage due to heating of the main layer (especially in the TD direction and the thickness direction)" caused by containing an inorganic filler, the use of fibers A quadruped zinc oxide grown in a three-dimensional direction is preferred.

In other words, this series of zinc oxide, which grows acicular single crystals from the center to the outside like a quadruped shape, grows radiantly from the center to the outside. Because it has a quadruped shape, compared with the case of using the same amount of fibrous potassium titanate, The suppression of "shrinkage caused by heating of the main layer in all directions" is further improved. Especially when using fibrous potassium titanate and tetrapod-shaped zinc oxide, the alignment of fibrous potassium titanate is disturbed by the tetrapod-shaped zinc oxide, not only in the MD direction but also in the TD direction and the thickness direction. The existence probability of the aligned fibrous potassium titanate is increased, so that the shrinkage suppression effect in all directions is more effectively improved.

Tetrapod-shaped zinc oxide, the average thickness of the single crystal extending radially is preferably 0.5 to 5 μm, the average length is preferably 5 to 30 μm, and the average thickness is preferably 1 to 3 μm, and the average length is 8 to 20 μm. . As such a commercially available product of the tetrapod-shaped zinc oxide, for example, zinc oxide single crystal (trade name: "Panatetra") manufactured by AmTech Corporation is mentioned as a preferable example.

In addition, when glass fiber is used as the inorganic filler, the rigidity of the base material for the transporting of the plating step can be increased, and the deflection of the transporting belt for the plating step can be suppressed in the same manner as the aforementioned subcomponent. In addition, when heat-treated (for example, about 200 ° C.) the substrate for conveyance in the plating step is transported, occurrence of ripples and deformation on the surface of the substrate can be suppressed.

The average thickness and average length of the inorganic filler are generally specified by observation with an electron microscope.

The content of the inorganic filler contained in the main layer is not particularly limited, but it is preferably 3 to 45% by mass, and more preferably 5 to 30% by mass. By setting it within this range, the effect of the inorganic filler can be obtained while ensuring the softness of the main layer, and the occurrence of wrinkles can be suppressed while being hard to become hard and brittle.

The thickness of the main layer is not particularly limited, but is preferably 10 to 100 μm, and more preferably 20 to 70 μm.

The manufacturing method of the main layer is not particularly limited. For example, a resin composition containing a resin component containing PBT as a main component and an inorganic filler can be prepared, and a desired thickness can be extruded by a T film method or an inflation method, and then formed. This makes it simple and easy.

As long as the effect of the present invention is not impaired, the main layer may contain additives such as an antistatic agent, an antiblocking agent, and a slip agent.

    (A form composed of a plurality of layers including a main layer)    

When the tape substrate for transportation in the plating step of the present invention is composed of a plurality of layers including a main layer, it is not only to prevent the inorganic filler contained in the main layer from falling off from the main layer during transportation and adhering to the flexible printed wiring board. Or, in order to reduce damage to the mold by the inorganic filler when forming multiple layers by simultaneous extrusion film formation, and from the viewpoint of forming a balanced layer with a base material-containing layer for the plating step, an example of the "main layer as The intermediate layer, and sandwiching the intermediate layer, a layer configuration in which the outer layer containing no inorganic filler is arranged in a symmetrical form "is a preferred example.

FIG. 1 is a schematic cross-sectional view showing an example of a tape substrate for transportation in the plating step of the present invention. In the substrate a of FIG. 1, 1 is an intermediate layer B, 2 is an outer layer A, and 3 is an outer layer C. With such a layer structure, in addition to suppressing the inorganic filler from falling off from the intermediate layer B as the main layer, from the viewpoint of layer structure balance, it is possible to suppress curl that occurs during or after film formation.

The intermediate layer B as the main layer is as described above.

As for the outer layer A and the outer layer C, those which do not contain any inorganic filler are preferred. The resin components of the outer layer A and the outer layer C are not particularly limited, but the resin components of the outer layer A and the outer layer C are from the viewpoint of being easy to simultaneously form three layers of the intermediate layer B, the outer layer A, and the outer layer C by extrusion molding. It is preferable that PBT is used as a main component similarly to the intermediate layer B.

That is, the resin components of the outer layer A and the outer layer C may be all composed of PBT, but when other resin components (subcomponents) are used in combination, the content of the resin components of the outer layer A and the outer layer C is 100% by mass so that the content of PBT is The main component (50% by mass or more) is preferred, 70% by mass or more is more preferred, and 85% by mass or more is particularly preferred. As the secondary component, at least one of PET, PEN, PC, and PBN can be used. In the present invention, when PBT and the aforementioned sub-components are contained in the intermediate layer B, the outer layer A and the outer layer C both preferably contain PBT and the aforementioned sub-components in the same manner as the intermediate layer B, especially from the viewpoint of layer composition Regardless of whether or not there is an inorganic filler, it is better that the resin composition of the intermediate layer B, the outer layer A and the outer layer C is the same.

The resin components of the outer layer A and the outer layer C are preferably free of PI. In the case where PI is contained and the content is high, the material of the PI film used for the flexible printed wiring board is the same or similar. Therefore, when the adhesive layer is provided and used as a transfer belt for the plating step, the adhesive layer may be used. The contained adhesive may be transferred (adhesive transferred) to the side of the flexible printed wiring board.

When the belt substrate for transport in the plating step of the present invention is composed of the three layers, the thickness of the outer layer A is not particularly limited, but is preferably 3 to 30 μm, and more preferably 5 to 15 μm. The thickness of the intermediate layer B is not particularly limited, but is preferably 5 to 60 μm, and more preferably 10 to 50 μm. In addition, the thickness of the outer layer C is not particularly limited, but is preferably 3 to 30 μm, and more preferably 5 to 15 μm. In addition, in terms of the balance of the layer constitutions, it is preferable that the thicknesses of the outer layer A and the outer layer C are the same.

In addition, the ratio of the layer thickness when the three layers are formed is preferably in the range of outer layer A: intermediate layer B: outer layer C = 1: 1: 1 to 1: 15: 1, so as to be 1: 2: 1. It is preferably within a range of 1: 8: 1. In addition, when the three-layer structure is used, the overall thickness is preferably 10 to 100 μm, and more preferably 20 to 70 μm.

The method for manufacturing the above-mentioned resin laminate is not particularly limited. For example, each resin composition for forming the outer layer A, the middle layer B, and the outer layer C can be prepared, and three layers can be extruded by the T film method or the inflation method. This makes it easy to manufacture. In addition, after each of the films of the outer layer A, the intermediate layer B, and the outer layer C is prepared, the respective films can be formed by laminating them by dry lamination using a known adhesive. Even in any manufacturing method, each layer and the resin laminate are unstretched films.

    2.Plating step transport belt    

The aforementioned tape substrate for transporting the plating step according to the present invention can be used as the tape for transporting the plating step b by providing the adhesive layer 4 as shown in FIG. 2 and FIG. 3. Specifically, an adhesive layer is provided on the surface of the base material for the transfer belt for the plating step, thereby forming a transfer belt for the plating step. Generally, it is sufficient to form an adhesive layer on one side of the substrate for conveyance with a plating step.

The method for imparting an adhesive layer is not particularly limited, and it can be formed by applying a known adhesive on the surface of the substrate for conveyance in the plating step.

Examples of the adhesive used to form the adhesive layer include rubber-based adhesives, acrylic-based adhesives, amine-based adhesives, and polyvinyl ether-based adhesives. Among them, acrylic-based adhesives are preferred.

Examples of the acrylic resin constituting the acrylic adhesive include a polymer of an alkyl (meth) acrylate, a copolymer of an alkyl (meth) acrylate, and a copolymerizable monomer thereof. In addition, (meth) acrylic means methacrylic acid or acrylic acid.

Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. , Octyl (meth) acrylate, isooctyl (meth) acrylate, and the like are preferably alkyl (meth) acrylates having a glass transition temperature of a homopolymer of -50 ° C or lower. In addition, as for an adhesive that is not easily deteriorated even in a heat treatment at approximately 200 ° C, butyl (meth) acrylate is preferred among alkyl (meth) acrylates.

Examples of the monomer copolymerizable with the alkyl (meth) acrylate include (meth) acrylic acid such as hydroxyethyl (meth) acrylate, hydroxybutyl (meth) acrylate, and hydroxyhexyl (meth) acrylate. Hydroxyalkyl acrylates; Dehydrated glyceryl (meth) acrylate, (meth) acrylic acid, itaconic acid, maleic anhydride, (meth) acrylamide, N-hydroxymethylammonium (meth) acrylate ; Alkylamino (meth) acrylates such as dimethylaminoethyl methacrylate, t-butylaminoethyl methacrylate, and the like; vinyl acetate, styrene, acrylonitrile, and the like.

The thickness of the adhesive layer is not particularly limited, but is preferably 1 to 30 μm, and more preferably 5 to 20 μm.

As shown in FIG. 4, the tape for transporting the plating step of the present invention thus obtained can be “adhered to the adhesive layer of the flexible printed wiring board 6 in the manufacturing process, and the transport roller 5 can be rotated to be transported. A plating bath is performed on the wiring substrate. " In addition to being transported to a plating tank, it can also be used for transporting to other steps as long as the durability of the transporting belt is not affected.

    [Example]    

Hereinafter, examples and comparative examples are listed to specifically explain the present invention. However, the present invention is not limited to the examples.

    <Examples 1, 3, 4, 9, 10 and Comparative Examples 1 to 4>    

The examples 1, 3, and 4 and the comparative examples 1 to 4 have only the intermediate layer B.

In the extruder, a resin component and an inorganic filler were added so as to be a blending combination described in Table 1, and melt-kneaded.

The film was extruded at 250 ° C. so that the thickness of the intermediate layer B was 40 μm.

The intermediate layer B is provided with an adhesive layer having a thickness of 10 μm.

Thereby, the tape base material for conveyance of a plating process is obtained.

    <Examples 2, 5 to 8, 11, 12>    

Examples 2, 5 to 8, 11, and 12 have an outer layer A, an intermediate layer B, and an outer layer C.

In each extruder of the three-layer extruder, a resin component and an inorganic filler were added so that each of the outer layer A, the intermediate layer B, and the outer layer C became the formulation combination described in Table 1, and melt-kneaded.

The outer layer A, the intermediate layer B, and the outer layer C were made into a thickness ratio of the outer layer A: the intermediate layer B: the outer layer C = 1: 3: 1, and the three layers were co-extruded at 250 ° C by an inflation method. A resin laminate having a thickness of 40 μm was obtained.

An adhesive layer having a thickness of 10 μm was provided on the outer layer A side.

Thereby, the tape base material for conveyance of a plating process is obtained.

    <Evaluation of the belt for conveyance in each plating step>         (With or without curl)    

For each plating step, a tape-coated adhesive ("ARONTAC S-1601" manufactured by Toa Kosei) is used to form a pressure-sensitive adhesive layer, and a flexible printed wiring board is attached and heated (approximately 200 ° C × 5 minutes), visually check for curl.

Those who did not recognize curl were evaluated as ◎, those who were slightly curled but still within the allowable range were evaluated as ○, and those who were significantly recognized as curl were evaluated as ×.

    (With or without glue transfer)    

For each plating step, a tape-coated adhesive ("ARONTAC S-1601" manufactured by Toa Kosei) is used to form a pressure-sensitive adhesive layer. After the flexible printed wiring board is attached, it is visually inspected during peeling. Observe whether there is any glue transfer to the flexible printed wiring board side.

Those who did not confirm the transfer of glue were evaluated as ○, and those who confirmed the transfer of glue were evaluated as ×.

    (Heat resistance)    

After heat-treating (200 ° C. × 5 minutes) the tape substrate for transport in each plating step, the surface of the substrate was visually observed for ripples and deformation.

Those with no corrugations and deformations were evaluated as ○, those with slight ripples and deformations that were within the allowable range in actual use were evaluated as △, and those that did not meet the allowable ranges were evaluated as ×.

    (Good or bad rigidity)    

The rigidity of the belt substrate for conveyance in each plating step was evaluated by the tensile elastic modulus (MPa).

A person with a tensile elastic modulus exceeding 1500 MPa was evaluated as ○, a person with a tensile elastic modulus of 1500 MPa or less and more than 900 MPa was evaluated as Δ, and a person with a tension of 900 MPa or less was evaluated as ×.

Each evaluation result is shown in Table 1.

It is clear from the results in Table 1 that the belts for the transport of the plating steps of Examples 1 to 12 that meet the predetermined requirements suppress the occurrence of curling during heat treatment after the formation of the adhesive layer, and suppress the occurrence of curl after the formation of the adhesive layer. Glue transfer occurs. With regard to Examples 1, 2, 4 to 12, the shrinkage in the MD direction was suppressed due to the use of the fibrous inorganic filler, and the shrinkage in the TD direction was also suppressed to a desired level. In addition, regarding Examples 3 to 12, the use of a tetrapod-shaped inorganic filler not only inhibited the shrinkage in the MD direction, but also suppressed the shrinkage in the TD direction and the thickness direction, thereby obtaining better shrinkage suppression. In addition, in Examples 7 and 8, in each of the outer layer A, the intermediate layer B, and the outer layer C, since PEN and PC were used in addition to PBT, the rigidity of the film was improved, and the heat resistance was also improved. .

On the other hand, the evaluation of occurrence of curl or occurrence of glue transfer of the belts for the transport of the plating steps of Comparative Examples 1 to 4 that did not meet the predetermined requirements was inferior to those of Examples 1 to 12. In particular, Comparative Examples 1 and 2 which do not contain the inorganic filler in the intermediate layer B are curled, and Comparative Example 3 which does not contain both PBT and the inorganic filler in the intermediate layer B is also curled. On the other hand, Comparative Example 4 in which PI was used in the intermediate layer but did not contain an inorganic filler was made of the same material as the PI film of the flexible printed wiring board, and the occurrence of curl was suppressed. However, it was confirmed that it was the same material. Transfer to glue.

PBT: "NOVADURAN‧5050CS" PEN film made by Mitsubishi Engineering-Plastics: "Teonex‧Q51" PET film made by Teijin DuPont Film Company: "Teijin Tetoron film‧G2" made by Teijin DuPont Company PI film: "Toray DuPont" Kapton‧50H "PEN (for mixing): Teijin DuPont's" Teonex TN 8065S "PC (for mixing): Teijin DuPont's" Pan light L-1250Y "PBN (for mixing): Teijin DuPont's PET (For mixing): "Bellpet‧DFG1" potassium titanate manufactured by Bell Polyester Products: "Tismo‧Tismo N (fiber diameter: 0.3 to 0.6 μm, fiber length: 10 to 20 μm)" manufactured by Otsuka Chemical Co., Ltd. Zinc oxide: Amtec "Panatetra‧WZ-0531 (average fiber length: approximately 10 μm, quadruped)" made by the company Glass fiber: "PF E-100 (without surface treatment)" made by Nittobo

Claims (11)

    A tape substrate for transporting a plating step is a substrate for forming a tape for transporting a plating step, wherein the tape for transporting the plating step is attached to a flexible printed wiring board and transported to a plating tank. And the user in the step of performing plating on the wiring substrate; (1) the substrate is a transfer belt for the plating step by providing an adhesive layer; (2) the substrate is composed of a single layer or a plurality of layers The unstretched film is composed, and at least one layer contains polybutylene terephthalate and an inorganic filler.         The substrate for conveyance of the plating step according to item 1 of the scope of the patent application, wherein the layer containing the aforementioned polybutylene terephthalate further contains a material selected from the group consisting of polyethylene terephthalate and polyethylene naphthalate. At least one of the group consisting of ethylene glycol, polycarbonate and polybutylene naphthalate.         The belt substrate for transporting a plating step according to item 1 or 2 of the scope of the patent application, wherein the inorganic filler contains fibrous potassium titanate.         The belt substrate for transport in the plating step according to item 3 of the scope of patent application, wherein the average thickness of the fibrous potassium titanate is 0.1 to 0.8 μm, the average length is 5 to 30 μm, and the average aspect ratio is 10 to 100.         The belt substrate for transporting a plating step according to any one of the scope of claims 1 to 4, wherein the aforementioned inorganic filler contains tetrapod-shaped zinc oxide.         The substrate for conveyance of a plating step according to any one of claims 1 to 5, wherein the inorganic filler contains glass fibers.         As described in any one of claims 1 to 6, the belt substrate for transporting the plating step is composed of a layer having an outer layer A, an intermediate layer B, and an outer layer C in order; (1 ) The intermediate layer B contains the polybutylene terephthalate and the inorganic filler; (2) The outer layer A and the outer layer C do not contain an inorganic filler.         The substrate for conveyance of the plating step according to item 7 of the scope of the patent application, wherein the outer layer A and the outer layer C contain the polybutylene terephthalate.         As described in item 8 of the scope of the patent application, the belt substrate for transporting the plating step, wherein the outer layer A, the intermediate layer B, and the outer layer C all further comprise a material selected from the group consisting of polyethylene terephthalate and polynaphthalene. At least one of the group consisting of ethylene formate, polycarbonate and polybutylene naphthalate.         As described in any one of claims 1 to 9 of the scope of the patent application, the belt substrate for transporting the plating step has a tensile elastic modulus of more than 1500 MPa and 2000 MPa or less.         A tape for transporting a plating step has an adhesive layer on a surface of a base material for the transport of a plating step according to any one of claims 1 to 10.